Summary:

The article presents the problem of inconsistencies of the lande borders under flowing waters and the shoreline of the river. It presents data register, containing information on the plots under the waters. These include the following databases: cadastral, topographic and administrative. Measurements of the course of the shoreline of one of the mountainous rivers showed large discrepancies between borders of land under the waters and the shoreline of the river. Changes in time and space of the shoreline of the river were determined on the basis of the long term cyclical location and height measurements. The paper aims to show the need of updating cadastral databases related to the borders of land under the flowing waters due to the change of the course of the rivers shoreline. Do cadastral maps always faithfully reflect the course of the border line of this type of objects? How often should they be updated? Cadastral maps as the primary source of information about the borders of land under the flowing waters (rivers) should be updated, after prior verification of the shoreline of the river (for example, on the basis of an orthophotomap). The study showed clearly, that update the borders of land under the waters should be performed at intervals of every 10 years.